2017 IJSRSET Volue 3 Issue 2 Print ISSN: 2395-1990 Online ISSN : 2394-4099 Theed Section: Engineering and Technology Weight Optiization and Finite Eleent Analysis of Pressure Vessel Due to Thickness Rashi S. Gaikwad, Mohaed Abdul Junaid, V. Sai Krishna, T. Keerthi Kuar Mechanical Departent, Lords Institute of Engineering and Technology, Hyderabad, Telangana, Andhra Pradesh, India ABSTRACT Finite Eleent Method is a atheatical technique used to carry out the stress analysis. In this ethod the solid odel of the coponent is subdivided into saller eleents. Constraints and loads are applied to the odel at specified locations. Various properties are assigned to the A pressure vessel is a closed container designed to hold gases or liquids at a pressure different fro the abient pressure. The end caps fitted to the cylindrical body are called heads. The ai of this paper to carry out detailed design & analysis of Pressure vessel used in boiler for optiu thickness, teperature distribution and dynaic behavior using Finite eleent analysis software. Model like aterial, thickness, etc. The odel is then analyzed in FE solver. The results are plotted in the post processor. Paper involves design of a cylindrical pressure vessel to sustain 5 bar pressure and deterine the wall thickness required for the vessel to liit the axiu shear stress. Geoetrical and finite eleent odel of Pressure vessel is created using CAD CAE tools. Geoetrical odel is created on CATIA V5R19 and finite eleent odeling is done using hyper esh. ANSYS is used as a solver. Weight optiization of pressure vessel due to thickness using FEA. Keywords: Pressure Vessel Due, Finite Eleent Analysis, CATIA V5R19, FEA, PED, ASME, AS1210 A. General Inforation I. INTRODUCTION A pressure vessel is a closed container designed to hold gases or liquids at a pressure different fro the abient pressure. The end caps fitted to the cylindrical body are called heads. Pressure vessels are used in a variety of applications. These include the industry and the private sector. They appear in these sectors respectively as industrial copressed air receivers and doestic hot water storage tanks, other exaples of pressure vessels are: diving cylinder, recopression chaber, distillation towers, autoclaves and any other vessels in ining or oil refineries and petrocheical plants, nuclear reactor vessel, habitat of a space ship, habitat of a subarine, pneuatic reservoir, hydraulic reservoir under pressure, rail vehicle airbrake reservoir, road vehicle airbrake reservoir and storage vessels for liquefied gases such as aonia, chlorine, propane, butane and LPG. A vessel that is inadequately designed to handle a high pressure constitutes a very significant safety hazard. Because of that, the design and certification of pressure vessels is governed by design codes such as the ASME Boiler and Pressure Vessel Code in North Aerica, the Pressure Equipent Directive of the EU (PED), Japanese Industrial Standard (JIS), CSA B51 in Canada, AS1210 in Australia and other international standards like Lloyd's, Geranischer Lloyd, Det Norske Veritas, Stoowezen etc. Pressure vessels can theoretically be alost any shape, but shapes ade of sections of spheres, cylinders and cones are usually eployed. More coplicated shapes have historically been uch harder to analyze for safe operation and are usually far harder to construct. Theoretically a sphere would be the optial shape of a pressure vessel. Unfortunately the sphere shape is difficult to anufacture, therefore ore expensive, so ost of the pressure vessels are cylindrical shape with 2:1 sei elliptical heads or end caps on each end. Saller pressure vessels are arranged fro a pipe and two covers. Disadvantage of these vessels is the fact that larger diaeters ake the relatively ore expensive, so that for exaple the ost econoic shape of a 1,000 liters (35 cu ft.), 250 bars (3,600 psi) pressure vessel ight be a diaeter of 914.4 illietres (36 in) and a IJSRSET162322 Received : 30 March 2017 Accepted : 09 April 2017 March-April-2017 [(3)2: 137-141] 1
length of 1,701.8 illietres (67 in) including the 2:1 sei elliptical doed end caps. Many pressure vessels are ade of steel. To anufacture a spherical pressure vessel, forged parts would have to be welded together. Soe echanical properties of steel are increased by forging, but welding can soeties reduce these desirable properties. In case of welding, in order to ake the pressure vessel eet international safety standards, carefully selected steel with a high ipact resistance & corrosion resistant aterial should also be used. Two types of analysis are coonly applied to pressure vessels. The ost Coon ethod is based on a siple echanics approach and is applicable to thin wall Pressure vessels which by definition have a ratio of inner radius, r, to wall thickness, t, of r/t 10. The second ethod is based on elasticity solution and is always applicable regardless the r/t ratio and can be referred to as the solution for Thick wall pressure vessels. Both types of analysis are discussed here, although for ost engineering applications, the thin wall pressure vessel can be used. II. LITERATURE REVIEW A. History The design of pressure vessels is an iportant and practical topic which has been explored for decades. Even though optiization techniques have been extensively applied to design structures in general, few pieces of work can be found which are directly related to optial pressure vessel design. These few references are ainly related to the design optiization of hoogeneous and coposite pressure vessels. B. Review of Papers Skopinsky and Setankin describe the structural odel and stress analysis of nozzle connections in ellipsoidal heads subjected to external loadings. They used Tioshenko shell theory and the finite eleent ethod. The features of the structural odel of ellipsoid-cylinder shell intersections, nuerical procedure and SAIS special-purpose coputer progra were discussed. A paraetric study of the effects of geoetric paraeters on the axiu effective stresses in the ellipsoidcylinder intersections under loading was perfored. The results of the stress analysis and paraetric study of the nozzle connections are presented [2]. Drazan, Pejo, Franjo and Darko (2010) considered influence of stresses resulting fro weld isalignent in cylindrical shell circuferential weld joint on the shell integrity.the stresses estiated analytically by API recoended practice procedure and calculated nuerically by using the finite eleent ethod. [3] L.You, J.Z hang and X. You present an accurate ethod to carry out elastic analysis of thick-walled spherical pressure vessels subjected to internal pressure. They considered two kinds of pressure vessels: one consists of two hoogeneous layers near the inner and outer surfaces of the vessel and one functionally graded layer in the iddle; the other consists of the functionally graded aterial only. They found that proposed approach converges very quickly and has excellent accuracy [7]. Carbonari, Munoz-Rojas (et al 2011) discuses work on shape optiization of axisyetric pressure vessels considering an integrated approach in which the entire pressure vessel odel is used in conjunction with a ulti-objective function that ais to iniize the von- Mises echanical stress fro nozzle to head. Representative exaples are exained and solutions obtained for the entire vessel considering teperature and pressure loading. A proper ulti-objective function based on a logarithic of a p-root of suation of p- exponent ters has been defined for iniizing the tank axiu von-mises stress [1]. Many works including analytical, experiental and nuerical investigations have been devoted to the stress analysis of nozzle connections in pressure vessels subjected to different external loadings. C. AIM OF PAPER A cylindrical pressure vessel, is to be used to generate stea at low pressure for a boiler dru. The vessel consists of a cylindrical portion with the two ends closed using heispherical structure. A nozzle is welded on at the id-point of the length of the vessel which is supported on two supports. The vessel is constructed using aterial low alloy steel of type ASME SA516Gr70. The internal pressure in the boiler is expected to be 5 bar. In addition, the flange of the nozzle is subjected to 439
forces and oents being transitted to the vessel through connected piping. The agnitudes of these forces and oents. ii. Material of Construction Shell Fx Fy Fz Mx My Mz (N) (N) (N) (N) (N) (N) 1500 1000 2000 650 600 500 Table 1: Forces and Moents Acting on the Flange of the Nozzle If possible optiize the weight using finite eleent analysis. Weight optiization in ters of aterial saving ust be the iportant paraeter. D. Design of Pressure Vessel Using As ME Boiler and Pressure Vessel Code i. Equipent Design Data Head Nozzle Support IS-2062-Plate Table 3: Material of Construction Design Calculations AS PER UG27 ti = + CA = + 1.5 UNITS DESIGN Internal pressure kg/²g 0.055 External pressure kg/²g 0 Maxiu tep C 300 Miniu tep C 25 Process density kg/³ 0 Radiography SHELL : SPOT 'T', HEAD: FULL Circ. Efficiency SHELL : 0.85, HEAD: 1 Long Efficiency SHELL : 0.85, HEAD: 1 C.A M 1.5 Polishing allowance Hydrostatic test pressure M 0 kg/²g 0.07308 Epty weight kg 1397.598 Operating weight Hydrostatic weight kg 1397.538 kg 8489.995 = 3.5445 + 1.5 = 5.0445 = Provided Thickness = 6 iii. Design of Heispherical Head: (Left) Design Conditions Code ASME- VIII DIV. 1,2010 Design pressure (internal) Pi 0.055 Design teperature T 300 Material of SA-516-70 plate construction Allowable stress S 13.758 @design tep. Radiography FULL Joint efficiency E 1 Allowance, corrosion CA 1.5 Inside diaeter of shell ID 1500 Table 4. Left Head Design Data E. Design Calculations As Per UG32f Table 2: Equipent Design Data Factor K = 0.5 t i = + CA + Thinning allowance 440
= + 1.5 + 0.48 = 1.5028 + 1.5 + 0.48 Code Design Pressure (internal) Design Tep. Max. Chord length ASME- VIII DIV. 1,2010 0.055 kg/²g 300 453 = 3.4828 Provided Thickness = 4 Nozzle outside weld Pad weld Table 9: Weld Data W1 W3 6.4 4. 24 2 Table 5:Material of Construction Nozzle Shell Pad Allowable stress @ design teperature Table 6: Nozzle Data Outside diaeter Inside diaeter Neck thickness (provided) Neck thickness (corroded) S n O D I D t n Table 7: Shell Data 13.758 kg/² 46 0 45 0 5 3. 5 Allowable stress @ design teperature Sv 13.758 kg/² Inside Radius (corroded) R 751.5 Thickness (corroded) Allowable stress @ design tep Table 8: Pad Data Sp t 4. 5 13.75 7 kg/² Outside diaeter Dp 573.409 Thickness Tp 6 tr = Table 10: Miniu Shell Thickness Required as per UG 37 Calculations as per UG 27 = = 3.0115 4.5.8 Neck Thickness as per UG45 (a) trn1 = = 0.918 4.5.9 Neck Thickness as per UG45 (b) trn 2= = 3.0115 F. Weight Optiization i. Weight Calculation by Using Thickness Calculated by ASME Code W eight of shell (Ws) = Developed length length of shell density thickness = 4.731 3 7.86 6 = 669.46 Kg Weight of heispherical dish (Wh) = 1.57 diaeter 2 density thickness = 1.57 1.5 2 7.86 4 = 111.06 Kg Weight of nozzle (Wn) = Developed length nozzle projection density thickness = 1.426 0.252 7.86 5 441
= 14.04 Kg Weight of flange (Wf) = ( OD 2 + ID 2 ) density thickness = (0.5602 + 0.4502 2 ) 7.86 27.873 = 20.57 Kg Weight of saddle (Wsaddle) = Weight of saddle, lifting lug and other accessories = 471.348 Kg Total weight = (ws) + 2 (wh) + (wf) + (wsaddle) = 669.46 + (2 111.06) + 14.04 +20.57 +471.348 = 1397.538 Kg ii. weight calculation by using thickness calculated by FEA weight of shell (Ws) SIGN PARAMETERS WEIGHT BY ASME CODE WEIGHT BY FEA (4KG) (KG) Weight of shell (ws) 669.46 445.75 Weight of dish(wh) 111.06 83.29 Weight of nozzle 14.04 11.21 (wn) Weight of flange 20.57 14.14 (wf) Weight of saddle 471.348 471.348 (wsaddle) Total Weight 1397.538 1109.03 Difference in 288.5 Weight = developed length length of shell density thickness = 4.725 3 7.86 4 = 475.75 kg Weight of heispherical dish (Wh) = 1.57 diaeter 2 density thickness = 1.57 1.5 2 7.86 3 = 83.29 Kg Weight of nozzle (Wn) = Developed length nozzle projection density thick. = 1.426 0.252 7.86 4 = 11.21 Kg Weight of flange (Wf) = ( OD 2 + ID 2 ) density thickness = (0.5602 + 0.4502 2 ) 7.86 20.64 = 14.15 Kg Weight of saddle (Wsaddle) = Weight of saddle, lifting lug and other accessories = 471.348 Kg Total weight = (ws) + 2 (wh) + (wf) + (wsaddle) = 445.75 + (2 83.29) + 11.21 +14.15 +471.348 = 1109.03 Kg Table 11: Weight Optiization Figure 1. Reduction of Weight in coparison of ASME and FEA III. CONCLUSION AND FUTURE SCOPE Design approach of pressure vessel are by ASME codes and Finite eleent analysis out of which analysis of Pressure vessel by FEA ethod is easy and get optiu paraeters. Design calculation of FEA is copare with ASME boiler and pressure vessel regulations. In Coparison of the results and design paraeters calculated by ASME boiler and pressure vessel code and finite eleent analysis are in thickness and reduces in weight of pressure vessel. Design by FEA is in weight reduction of pressure vessel Optiize design by FEA reduces the total Cost of pressure vessel. 442
The optiization in design of pressure vessel using FEA is safe and has successfully satisfied the goal of econoics. IV. ACKNOWLEDGEMENT I gratefully acknowledge Departent of Mechanical Engineering of Lords Institute Engineering and Technology, Hyderabad for technical support and providing there search facilities. I would also like to thank to Aza Pasha H.O.D., Pralhad.M.Hadnoor for Their help and dedication toward y research and related research, also y friends for their directly & indirectly help, support and excellent co-operation. V. REFERENCES [1]. Carbonari, Munoz-Rojas, Andrade, Paulino, Nishioto, Silva, Design of pressure vessels using shape optiization: An integrated approach, International Journal of Pressure Vessels and Piping, Volue 88, May 2011, Page no.198-212. [2]. Skopinsky and Setankin, Modeling and Stress analysis of nozzle connections in Ellipsoidal heads of Pressure vessels under External loading International Journal of Applied Mechanics and Engineering, 2006, vol.11, No.4, Page no. 965-979. [3]. Drazan Kozak, Franjo Matejicek, Darko Dajanovic, Weld isalignent influence on structural integrity of Cylindrical Pressure Vessel, Structural integrity and life, Vol. 10, No 2, 2010, Page no. 153-159. [4]. Vince Adas and Abraha Ashkenazi, Building better products with finite eleent analysis, 1st edition, onward press, USA, 1999. 443